1. Field of the Invention
The present invention relates to a novel polyorganosiloxane compound suitable for modifying synthetic resins.
2. Description of Related Art
Heretofore, silicone resins have been employed for providing synthetic resin molded products with various characteristics including surface properties such as water repellency, mold releasability and antifouling property inherent in siloxane compounds as well as thermal resistance. These silicone resins are mainly composed of linear polysiloxane compounds. The linear polysiloxane compounds are blended if they do not possess a group or they are chemically introduced into the resins if they possess a group or groups reactive therewith.
Increasing attention has recently been paid to polysiloxane compounds which may be used as raw materials of graft polymers for modifying synthetic resins. As such, polysiloxane compounds have been mainly employed as so-called "polysiloxane compounds modified at one terminal" in which a functional group resides at only one of the terminals and a trimethylsiloxy group resides at the other terminal.
When the polysiloxane compounds are used with the attempt to improve characteristics of synthetic resins in order to satisfy recent demands for higher functional characteristics, they suffer the disadvantages that sufficient improvements in characteristics of the synthetic resins cannot be achieved or a large quantity of the polysiloxanes must be added to achieve characteristics sought to be performed by addition, thereby adversely affecting other characteristics, because the conventional polysiloxane compounds rely on improvements in properties upon their inherent functions.
When there is used a polysiloxane compound wherein both of its terminals are provided with the same substituents which are not reactive with the objective synthetic resin, i.e., a so-called "polysiloxane compound modified at both terminals", it presents the problems that an amount of the polysiloxane compound to be added cannot be increased on account of bleeding and fluctuations in characteristics which may occur to a remarkably large extent as time elapses, whereby the expected characteristics cannot be maintained for a long period of time.
On the contrary, when the polysiloxane modified at both terminals with substituents is reactive with the synthetic resins which are used for their surface modifications, it also poses the difficulty that a large amount of the polysiloxane compound should be added to achieve the properties as required, thereby resulting in a remarkable reduction in other properties. Furthermore, it is difficult to use these polysiloxane compounds modified at both terminals as graft polymers which has recently drawn increasing attention for modifying surfaces of the synthetic resins.
In the polysiloxane compound modified at its one terminal, a group at its one terminal which is not reactive with the synthetic resins is generally constituted by trimethylsiloxy group, and modifications of characteristics for the synthetic resins are dependent upon the properties of the polysiloxane compound itself. Therefore, demands for higher functions are not achieved to a sufficient extent or a large amount of the polysiloxane compound should be added in order to satisfy the characteristics sought to be attained, thus adversely affecting other properties.
It is further to be noted that dimethylsiloxane alone, in which its terminal is terminated by the trimethylsiloxy group, can little improve oil repellency.